As the volume and complexity of vehicular traffic has continued to increase worldwide, so has the need for collision warning systems to help vehicle drivers avoid collisions. Examples of collision warning systems include forward collision warning systems, blind spot warning systems, lane departure warning systems, intersection collision warning systems, and pedestrian detection systems. Typically, many of these systems employ radar sensors, or a combination of radar and vision sensors to perform vehicle detection and recognition.
One problem typically associated with a “radar only” approach to vehicle detection is multiple false positives, which is the indication of the presence of a vehicle in an area when no vehicle is actually present in that area. Another problem with “radar only” systems is that the placement of bounding boxes, which typically are designed to indicate the approximate location and boundaries of an area containing a target vehicle, can be imprecise. Some designers have attempted to address these shortcomings by combining radar with vision sensors, often using the radar as a cueing system to locate potential vehicle areas and provide located potential vehicle areas to a vision-based portion of the sensor to complete processing and identify the vehicles. While this approach can be effective, it has the disadvantage of requiring both radar hardware and vision/camera hardware, adding expense to the system.
What is needed is a fast cueing video-only system for detecting and identifying regions of interest that are potential vehicles and/or objects in an input image frame, and passing region of interest information on to additional processing circuitry for classification and processing.